Thermoplastic roofing membranes, such as polyvinyl chloride (PVC) and thermoplastic polyolefin (TPO), are a rapidly growing in market acceptance. Thermoplastic standing seam profiles are designed to add aesthetics to otherwise plain thermoplastic roofing membrane. The standing seam profile thermoplastic roof assembly resembles a standing seam metal roof with the advantages of true waterproof performance, lower installed cost, sound and hail resistance. It can be applied for broad roof shapes, especially for curved roof installation. To enhance the appearance of such roofs, thermoplastic standing seam profiles (SSP) have been secured to the thermoplastic membranes, sometimes by adhesive, and sometimes by the application of heat, all of which is done manually. One of the key success factors is the secure attachment of thermoplastic standing seam profile to thermoplastic membrane without roof penetration. Utilizing peel & stick adhesive tape technology is an easy and quick installation method. However, long-term tape attachment is a concern encountering uneven roof substrate and building movement.
Utilizing a heat welding machine or hand gun requires a wide and flexible thermoplastic profile flange for conventional roofing heat welding practice. An alternative is to use a customized heat welding apparatus which have means to overcome central upstanding profile and to weld thermoplastic standing seam profile to thermoplastic roofing membrane. Applying heat to permanently attach the profiles may require a welder that is large and cumbersome. For a steep sloped roof, this is especially challenging. Also, the roofer will be required to guide the system in a straight line to achieve a good appearance, while keeping the profile in place, and maintaining a balance on a sloped roof.
Extrusion welding is a manual welding process and as such, is dependent on operator skill. Unfortunately, manual application of the strips is a time consuming and labor intensive process, increasing the cost of the roofing and decreasing the cost advantage gained by selecting thermoplastic roofing over metal roofing. Manual application also increases opportunity for error and is not conducive to creating straight and/or parallel and/or equidistant lines.
Extrusion welders are designed to maximize weld quality by ensuring certain parameters are accurately defined, such as, temperature of the welding material (extrudate), mass flow rate of the welding material, temperature of the hot gas for substrate pre-heat, and quantity of hot gas. The speed of welding is dependent on the flow rate of the extrudate, the material thickness, the cross sectional area of the seam and the size and design of the welding shoe.
What is needed in the art is a quick and inexpensive apparatus and method of attaching thermoplastic strips to thermoplastic roofing membranes.